This invention relates generally to methods of manufacturing flat panel displays, and more particularly to methods of manufacturing field emission displays.
A field emission display (FED) is a flat panel display that has a transparent faceplate with phosphor coated pixels, and a cathode having a large number of microtip emitters that can be activated to emit electrons to excite the phosphors. The cathode can be attached to or integrally formed with a backplate; alternatively, the cathode can be attached to the faceplate and enclosed by a backplate assembly sealed to the faceplate. In either case, the cathode must be aligned carefully with the faceplate so that the cathode emitters are disposed across from the specific pixels they are supposed to activate. The alignment must be very fine, e.g., 6-8 microns for a 12 inch (30 cm) display, which is on the order of one part in 10.sup.5. Because the display must operate in a vacuum, a vacuum seal is made between the backplate and the faceplate. Aligning and maintaining alignment while making a vacuum seal in a high resolution, large area display is a serious problem.
Some types of display devices, such as plasma displays, do not require particularly accurate alignment. It is much easier to seal a display device without the need for careful alignment. For high accuracy alignment applications, it has also been proposed that the alignment and sealing be done simultaneously in a vacuum chamber. Such a process, however, would likely be time-consuming and unsuitable for large-scale manufacture because the aligning and sealing would both have to be done one assembly at a time.